Military units thought to be loyal to Iraqi Prime Minister Nouri al-Maliki have been deployed in Baghdad as other politicians are moving to remove him from office, reports say. In Iraq's government the prime minister is the head of state but must be nominated for leadership after national elections by the country's president. Current President Fouad Massoum has decided to nominate Haider al-Abadi (who, like Maliki, is a Shiite), but the incumbent prime minister insists that he has a right to a third term.

At issue, apparently, is the question of which parliamentary delegation counts as the country's largest—Maliki's particular Shiite group or a broader Shiite alliance. Iraq's highest court has weighed in on the question. From Reuters:

Without naming any political group, the judges said that, under the constitution, the biggest group in parliament should be given the first opportunity to nominate a prime minister.

A key point is whether Maliki's State of Law is that biggest group or whether the designation belongs to a broader Shi'ite coalition known as the National Alliance, of which State of Law is part. The court, by referring to the rights of the biggest group that took part in a first session of the new legislature on July 1, seemed to favor Maliki, since the National Alliance failed to register as a parliamentary unit on that occasion.

Amid ongoing fighting with ISIS in northern Iraq, Maliki responded to the constitutional crisis by deploying units thought to be personally loyal to him: "On Sunday, a defiant Mr. Maliki mustered Iraqi forces in Baghdad’s government center, known as the Green Zone, in a show of force meant to intimidate Mr. Massoum and other leading political figures," the New York Times reports. The Times, though, identifies three other factions within the Iraqi army—including Kurdish troops, who are currently battling ISIS—who could move to push Maliki out.

The United States, via Secretary of State John Kerry, backed Massoum's efforts to form a new government and warned Maliki not to use force in an attempt to retain power.